/rust/registry/src/index.crates.io-6f17d22bba15001f/ryu-1.0.19/src/pretty/mod.rs

Source (jump to first uncovered line)
mod exponent;
mod mantissa;

use self::exponent::{write_exponent2, write_exponent3};
use self::mantissa::{write_mantissa, write_mantissa_long};
use crate::common;
use crate::d2s::{self, d2d, DOUBLE_EXPONENT_BITS, DOUBLE_MANTISSA_BITS};
use crate::f2s::{f2d, FLOAT_EXPONENT_BITS, FLOAT_MANTISSA_BITS};
use core::ptr;
#[cfg(feature = "no-panic")]
use no_panic::no_panic;

/// Print f64 to the given buffer and return number of bytes written.
///
/// At most 24 bytes will be written.
///
/// ## Special cases
///
/// This function **does not** check for NaN or infinity. If the input
/// number is not a finite float, the printed representation will be some
/// correctly formatted but unspecified numerical value.
///
/// Please check [`is_finite`] yourself before calling this function, or
/// check [`is_nan`] and [`is_infinite`] and handle those cases yourself.
///
/// [`is_finite`]: https://doc.rust-lang.org/std/primitive.f64.html#method.is_finite
/// [`is_nan`]: https://doc.rust-lang.org/std/primitive.f64.html#method.is_nan
/// [`is_infinite`]: https://doc.rust-lang.org/std/primitive.f64.html#method.is_infinite
///
/// ## Safety
///
/// The `result` pointer argument must point to sufficiently many writable bytes
/// to hold Ryū's representation of `f`.
///
/// ## Example
///
/// ```
/// use std::{mem::MaybeUninit, slice, str};
///
/// let f = 1.234f64;
///
/// unsafe {
///     let mut buffer = [MaybeUninit::<u8>::uninit(); 24];
///     let len = ryu::raw::format64(f, buffer.as_mut_ptr() as *mut u8);
///     let slice = slice::from_raw_parts(buffer.as_ptr() as *const u8, len);
///     let print = str::from_utf8_unchecked(slice);
///     assert_eq!(print, "1.234");
/// }
/// ```
#[must_use]
#[cfg_attr(feature = "no-panic", no_panic)]
pub unsafe fn format64(f: f64, result: *mut u8) -> usize {
    let bits = f.to_bits();
    let sign = ((bits >> (DOUBLE_MANTISSA_BITS + DOUBLE_EXPONENT_BITS)) & 1) != 0;
    let ieee_mantissa = bits & ((1u64 << DOUBLE_MANTISSA_BITS) - 1);
    let ieee_exponent =
        (bits >> DOUBLE_MANTISSA_BITS) as u32 & ((1u32 << DOUBLE_EXPONENT_BITS) - 1);

    let mut index = 0isize;
    if sign {
        *result = b'-';
        index += 1;
    }

    if ieee_exponent == 0 && ieee_mantissa == 0 {
        ptr::copy_nonoverlapping(b"0.0".as_ptr(), result.offset(index), 3);
        return sign as usize + 3;
    }

    let v = d2d(ieee_mantissa, ieee_exponent);

    let length = d2s::decimal_length17(v.mantissa) as isize;
    let k = v.exponent as isize;
    let kk = length + k; // 10^(kk-1) <= v < 10^kk
    debug_assert!(k >= -324);

    if 0 <= k && kk <= 16 {
        // 1234e7 -> 12340000000.0
        write_mantissa_long(v.mantissa, result.offset(index + length));
        for i in length..kk {
            *result.offset(index + i) = b'0';
        }
        *result.offset(index + kk) = b'.';
        *result.offset(index + kk + 1) = b'0';
        index as usize + kk as usize + 2
    } else if 0 < kk && kk <= 16 {
        // 1234e-2 -> 12.34
        write_mantissa_long(v.mantissa, result.offset(index + length + 1));
        ptr::copy(result.offset(index + 1), result.offset(index), kk as usize);
        *result.offset(index + kk) = b'.';
        index as usize + length as usize + 1
    } else if -5 < kk && kk <= 0 {
        // 1234e-6 -> 0.001234
        *result.offset(index) = b'0';
        *result.offset(index + 1) = b'.';
        let offset = 2 - kk;
        for i in 2..offset {
            *result.offset(index + i) = b'0';
        }
        write_mantissa_long(v.mantissa, result.offset(index + length + offset));
        index as usize + length as usize + offset as usize
    } else if length == 1 {
        // 1e30
        *result.offset(index) = b'0' + v.mantissa as u8;
        *result.offset(index + 1) = b'e';
        index as usize + 2 + write_exponent3(kk - 1, result.offset(index + 2))
    } else {
        // 1234e30 -> 1.234e33
        write_mantissa_long(v.mantissa, result.offset(index + length + 1));
        *result.offset(index) = *result.offset(index + 1);
        *result.offset(index + 1) = b'.';
        *result.offset(index + length + 1) = b'e';
        index as usize
            + length as usize
            + 2
            + write_exponent3(kk - 1, result.offset(index + length + 2))
    }
}

/// Print f32 to the given buffer and return number of bytes written.
///
/// At most 16 bytes will be written.
///
/// ## Special cases
///
/// This function **does not** check for NaN or infinity. If the input
/// number is not a finite float, the printed representation will be some
/// correctly formatted but unspecified numerical value.
///
/// Please check [`is_finite`] yourself before calling this function, or
/// check [`is_nan`] and [`is_infinite`] and handle those cases yourself.
///
/// [`is_finite`]: https://doc.rust-lang.org/std/primitive.f32.html#method.is_finite
/// [`is_nan`]: https://doc.rust-lang.org/std/primitive.f32.html#method.is_nan
/// [`is_infinite`]: https://doc.rust-lang.org/std/primitive.f32.html#method.is_infinite
///
/// ## Safety
///
/// The `result` pointer argument must point to sufficiently many writable bytes
/// to hold Ryū's representation of `f`.
///
/// ## Example
///
/// ```
/// use std::{mem::MaybeUninit, slice, str};
///
/// let f = 1.234f32;
///
/// unsafe {
///     let mut buffer = [MaybeUninit::<u8>::uninit(); 16];
///     let len = ryu::raw::format32(f, buffer.as_mut_ptr() as *mut u8);
///     let slice = slice::from_raw_parts(buffer.as_ptr() as *const u8, len);
///     let print = str::from_utf8_unchecked(slice);
///     assert_eq!(print, "1.234");
/// }
/// ```
#[must_use]
#[cfg_attr(feature = "no-panic", no_panic)]
pub unsafe fn format32(f: f32, result: *mut u8) -> usize {
    let bits = f.to_bits();
    let sign = ((bits >> (FLOAT_MANTISSA_BITS + FLOAT_EXPONENT_BITS)) & 1) != 0;
    let ieee_mantissa = bits & ((1u32 << FLOAT_MANTISSA_BITS) - 1);
    let ieee_exponent = (bits >> FLOAT_MANTISSA_BITS) & ((1u32 << FLOAT_EXPONENT_BITS) - 1);

    let mut index = 0isize;
    if sign {
        *result = b'-';
        index += 1;
    }

    if ieee_exponent == 0 && ieee_mantissa == 0 {
        ptr::copy_nonoverlapping(b"0.0".as_ptr(), result.offset(index), 3);
        return sign as usize + 3;
    }

    let v = f2d(ieee_mantissa, ieee_exponent);

    let length = common::decimal_length9(v.mantissa) as isize;
    let k = v.exponent as isize;
    let kk = length + k; // 10^(kk-1) <= v < 10^kk
    debug_assert!(k >= -45);

    if 0 <= k && kk <= 13 {
        // 1234e7 -> 12340000000.0
        write_mantissa(v.mantissa, result.offset(index + length));
        for i in length..kk {
            *result.offset(index + i) = b'0';
        }
        *result.offset(index + kk) = b'.';
        *result.offset(index + kk + 1) = b'0';
        index as usize + kk as usize + 2
    } else if 0 < kk && kk <= 13 {
        // 1234e-2 -> 12.34
        write_mantissa(v.mantissa, result.offset(index + length + 1));
        ptr::copy(result.offset(index + 1), result.offset(index), kk as usize);
        *result.offset(index + kk) = b'.';
        index as usize + length as usize + 1
    } else if -6 < kk && kk <= 0 {
        // 1234e-6 -> 0.001234
        *result.offset(index) = b'0';
        *result.offset(index + 1) = b'.';
        let offset = 2 - kk;
        for i in 2..offset {
            *result.offset(index + i) = b'0';
        }
        write_mantissa(v.mantissa, result.offset(index + length + offset));
        index as usize + length as usize + offset as usize
    } else if length == 1 {
        // 1e30
        *result.offset(index) = b'0' + v.mantissa as u8;
        *result.offset(index + 1) = b'e';
        index as usize + 2 + write_exponent2(kk - 1, result.offset(index + 2))
    } else {
        // 1234e30 -> 1.234e33
        write_mantissa(v.mantissa, result.offset(index + length + 1));
        *result.offset(index) = *result.offset(index + 1);
        *result.offset(index + 1) = b'.';
        *result.offset(index + length + 1) = b'e';
        index as usize
            + length as usize
            + 2
            + write_exponent2(kk - 1, result.offset(index + length + 2))
    }
}

Coverage Report

Created: 2025-07-11 06:39

Line	Count	Source (jump to first uncovered line)
1		mod exponent;
2		mod mantissa;
3
4		use self::exponent::{write_exponent2, write_exponent3};
5		use self::mantissa::{write_mantissa, write_mantissa_long};
6		use crate::common;
7		use crate::d2s::{self, d2d, DOUBLE_EXPONENT_BITS, DOUBLE_MANTISSA_BITS};
8		use crate::f2s::{f2d, FLOAT_EXPONENT_BITS, FLOAT_MANTISSA_BITS};
9		use core::ptr;
10		#[cfg(feature = "no-panic")]
11		use no_panic::no_panic;
12
13		/// Print f64 to the given buffer and return number of bytes written.
14		///
15		/// At most 24 bytes will be written.
16		///
17		/// ## Special cases
18		///
19		/// This function does not check for NaN or infinity. If the input
20		/// number is not a finite float, the printed representation will be some
21		/// correctly formatted but unspecified numerical value.
22		///
23		/// Please check [`is_finite`] yourself before calling this function, or
24		/// check [`is_nan`] and [`is_infinite`] and handle those cases yourself.
25		///
26		/// [`is_finite`]: https://doc.rust-lang.org/std/primitive.f64.html#method.is_finite
27		/// [`is_nan`]: https://doc.rust-lang.org/std/primitive.f64.html#method.is_nan
28		/// [`is_infinite`]: https://doc.rust-lang.org/std/primitive.f64.html#method.is_infinite
29		///
30		/// ## Safety
31		///
32		/// The `result` pointer argument must point to sufficiently many writable bytes
33		/// to hold Ryū's representation of `f`.
34		///
35		/// ## Example
36		///
37		/// ```
38		/// use std::{mem::MaybeUninit, slice, str};
39		///
40		/// let f = 1.234f64;
41		///
42		/// unsafe {
43		/// let mut buffer = [MaybeUninit::<u8>::uninit(); 24];
44		/// let len = ryu::raw::format64(f, buffer.as_mut_ptr() as *mut u8);
45		/// let slice = slice::from_raw_parts(buffer.as_ptr() as *const u8, len);
46		/// let print = str::from_utf8_unchecked(slice);
47		/// assert_eq!(print, "1.234");
48		/// }
49		/// ```
50		#[must_use]
51		#[cfg_attr(feature = "no-panic", no_panic)]
52	0	pub unsafe fn format64(f: f64, result: *mut u8) -> usize {
53	0	let bits = f.to_bits();
54	0	let sign = ((bits >> (DOUBLE_MANTISSA_BITS + DOUBLE_EXPONENT_BITS)) & 1) != 0;
55	0	let ieee_mantissa = bits & ((1u64 << DOUBLE_MANTISSA_BITS) - 1);
56	0	let ieee_exponent =
57	0	(bits >> DOUBLE_MANTISSA_BITS) as u32 & ((1u32 << DOUBLE_EXPONENT_BITS) - 1);
58	0
59	0	let mut index = 0isize;
60	0	if sign {
61	0	*result = b'-';
62	0	index += 1;
63	0	}
64
65	0	if ieee_exponent == 0 && ieee_mantissa == 0 {
66	0	ptr::copy_nonoverlapping(b"0.0".as_ptr(), result.offset(index), 3);
67	0	return sign as usize + 3;
68	0	}
69	0
70	0	let v = d2d(ieee_mantissa, ieee_exponent);
71	0
72	0	let length = d2s::decimal_length17(v.mantissa) as isize;
73	0	let k = v.exponent as isize;
74	0	let kk = length + k; // 10^(kk-1) <= v < 10^kk
75	0	debug_assert!(k >= -324);
76
77	0	if 0 <= k && kk <= 16 {
78		// 1234e7 -> 12340000000.0
79	0	write_mantissa_long(v.mantissa, result.offset(index + length));
80	0	for i in length..kk {
81	0	*result.offset(index + i) = b'0';
82	0	}
83	0	*result.offset(index + kk) = b'.';
84	0	*result.offset(index + kk + 1) = b'0';
85	0	index as usize + kk as usize + 2
86	0	} else if 0 < kk && kk <= 16 {
87		// 1234e-2 -> 12.34
88	0	write_mantissa_long(v.mantissa, result.offset(index + length + 1));
89	0	ptr::copy(result.offset(index + 1), result.offset(index), kk as usize);
90	0	*result.offset(index + kk) = b'.';
91	0	index as usize + length as usize + 1
92	0	} else if -5 < kk && kk <= 0 {
93		// 1234e-6 -> 0.001234
94	0	*result.offset(index) = b'0';
95	0	*result.offset(index + 1) = b'.';
96	0	let offset = 2 - kk;
97	0	for i in 2..offset {
98	0	*result.offset(index + i) = b'0';
99	0	}
100	0	write_mantissa_long(v.mantissa, result.offset(index + length + offset));
101	0	index as usize + length as usize + offset as usize
102	0	} else if length == 1 {
103		// 1e30
104	0	*result.offset(index) = b'0' + v.mantissa as u8;
105	0	*result.offset(index + 1) = b'e';
106	0	index as usize + 2 + write_exponent3(kk - 1, result.offset(index + 2))
107		} else {
108		// 1234e30 -> 1.234e33
109	0	write_mantissa_long(v.mantissa, result.offset(index + length + 1));
110	0	result.offset(index) = result.offset(index + 1);
111	0	*result.offset(index + 1) = b'.';
112	0	*result.offset(index + length + 1) = b'e';
113	0	index as usize
114	0	+ length as usize
115	0	+ 2
116	0	+ write_exponent3(kk - 1, result.offset(index + length + 2))
117		}
118	0	}
119
120		/// Print f32 to the given buffer and return number of bytes written.
121		///
122		/// At most 16 bytes will be written.
123		///
124		/// ## Special cases
125		///
126		/// This function does not check for NaN or infinity. If the input
127		/// number is not a finite float, the printed representation will be some
128		/// correctly formatted but unspecified numerical value.
129		///
130		/// Please check [`is_finite`] yourself before calling this function, or
131		/// check [`is_nan`] and [`is_infinite`] and handle those cases yourself.
132		///
133		/// [`is_finite`]: https://doc.rust-lang.org/std/primitive.f32.html#method.is_finite
134		/// [`is_nan`]: https://doc.rust-lang.org/std/primitive.f32.html#method.is_nan
135		/// [`is_infinite`]: https://doc.rust-lang.org/std/primitive.f32.html#method.is_infinite
136		///
137		/// ## Safety
138		///
139		/// The `result` pointer argument must point to sufficiently many writable bytes
140		/// to hold Ryū's representation of `f`.
141		///
142		/// ## Example
143		///
144		/// ```
145		/// use std::{mem::MaybeUninit, slice, str};
146		///
147		/// let f = 1.234f32;
148		///
149		/// unsafe {
150		/// let mut buffer = [MaybeUninit::<u8>::uninit(); 16];
151		/// let len = ryu::raw::format32(f, buffer.as_mut_ptr() as *mut u8);
152		/// let slice = slice::from_raw_parts(buffer.as_ptr() as *const u8, len);
153		/// let print = str::from_utf8_unchecked(slice);
154		/// assert_eq!(print, "1.234");
155		/// }
156		/// ```
157		#[must_use]
158		#[cfg_attr(feature = "no-panic", no_panic)]
159	0	pub unsafe fn format32(f: f32, result: *mut u8) -> usize {
160	0	let bits = f.to_bits();
161	0	let sign = ((bits >> (FLOAT_MANTISSA_BITS + FLOAT_EXPONENT_BITS)) & 1) != 0;
162	0	let ieee_mantissa = bits & ((1u32 << FLOAT_MANTISSA_BITS) - 1);
163	0	let ieee_exponent = (bits >> FLOAT_MANTISSA_BITS) & ((1u32 << FLOAT_EXPONENT_BITS) - 1);
164	0
165	0	let mut index = 0isize;
166	0	if sign {
167	0	*result = b'-';
168	0	index += 1;
169	0	}
170
171	0	if ieee_exponent == 0 && ieee_mantissa == 0 {
172	0	ptr::copy_nonoverlapping(b"0.0".as_ptr(), result.offset(index), 3);
173	0	return sign as usize + 3;
174	0	}
175	0
176	0	let v = f2d(ieee_mantissa, ieee_exponent);
177	0
178	0	let length = common::decimal_length9(v.mantissa) as isize;
179	0	let k = v.exponent as isize;
180	0	let kk = length + k; // 10^(kk-1) <= v < 10^kk
181	0	debug_assert!(k >= -45);
182
183	0	if 0 <= k && kk <= 13 {
184		// 1234e7 -> 12340000000.0
185	0	write_mantissa(v.mantissa, result.offset(index + length));
186	0	for i in length..kk {
187	0	*result.offset(index + i) = b'0';
188	0	}
189	0	*result.offset(index + kk) = b'.';
190	0	*result.offset(index + kk + 1) = b'0';
191	0	index as usize + kk as usize + 2
192	0	} else if 0 < kk && kk <= 13 {
193		// 1234e-2 -> 12.34
194	0	write_mantissa(v.mantissa, result.offset(index + length + 1));
195	0	ptr::copy(result.offset(index + 1), result.offset(index), kk as usize);
196	0	*result.offset(index + kk) = b'.';
197	0	index as usize + length as usize + 1
198	0	} else if -6 < kk && kk <= 0 {
199		// 1234e-6 -> 0.001234
200	0	*result.offset(index) = b'0';
201	0	*result.offset(index + 1) = b'.';
202	0	let offset = 2 - kk;
203	0	for i in 2..offset {
204	0	*result.offset(index + i) = b'0';
205	0	}
206	0	write_mantissa(v.mantissa, result.offset(index + length + offset));
207	0	index as usize + length as usize + offset as usize
208	0	} else if length == 1 {
209		// 1e30
210	0	*result.offset(index) = b'0' + v.mantissa as u8;
211	0	*result.offset(index + 1) = b'e';
212	0	index as usize + 2 + write_exponent2(kk - 1, result.offset(index + 2))
213		} else {
214		// 1234e30 -> 1.234e33
215	0	write_mantissa(v.mantissa, result.offset(index + length + 1));
216	0	result.offset(index) = result.offset(index + 1);
217	0	*result.offset(index + 1) = b'.';
218	0	*result.offset(index + length + 1) = b'e';
219	0	index as usize
220	0	+ length as usize
221	0	+ 2
222	0	+ write_exponent2(kk - 1, result.offset(index + length + 2))
223		}
224	0	}